Computational Fluid Dynamics Studies on Unstable Oscillatory Direct Contact Condensation of Subsonic Steam Jets in Water Cross-Flow

Abstract

In the last decade, researchers working on direct contact condensation (DCC) have focused their attention on studying the effect of liquid cross-flow, in contrast to the conventional stagnant liquid pool condensers. Currently, the major applications of DCC in liquid cross-flow include the sterilization process of milk and the mixing of oxygen-rich turbine drive gas with liquid oxygen (LOX) at the booster turbopump exit of a typical staged combustion cycle-based rocket engine. In this work, attempt has been made to develop and validate a two-fluid two-phase model for predicting the complex phenomena of steam injection into a cross-flow of subcooled water. A correlation for interaction length scale has been developed for DCC cases. The correlation includes the effect of all the critical operating parameters such as liquid subcooling, steam mass flux, and liquid velocity, which hitherto has not been available in the literature. The unstable nature of steam plumes has been investigated, and critical Weber numbers for predicting stable to unstable transition in a DCC cycle have been computed. The associated pressure and temperature oscillations due to unstable nature of plume have been studied. The critical design parameters for direct contact condenser such as the heat transfer coefficients and dimensionless vapor penetration lengths have been quantified and analyzed.